990
ACUS02 KWNS 241735
SWODY2
SPC AC 241733

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1233 PM CDT Fri Jul 24 2026

Valid 251200Z - 261200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ROM THE
NORTHERN ROCKIES INTO THE UPPER MIDWEST...AND ACROSS PORTIONS OF
SOUTHEAST ARIZONA...

...SUMMARY...
Isolated severe storms will be possible from the northern Rockies
into the upper Midwest, and across portions of southeast Arizona.

...Synopsis...
A belt of enhanced mid-level flow will move around the northern
periphery of the high amplitude ridge across the central US
D2/Saturday. Southwesterly mid-level flow will overspread portions
of the northern Rockies, with more northwesterly flow shifting
across the Upper Midwest into the Great Lakes Region.  At the
surface, a weak front will extend from a surface low over the
northern and central Plains to the Southeast coastal areas.

...Northern Rockies...
Deeply mixed boundary layer conditions are expected across the
Northern Rockies amid dry sub-cloud inverted-v soundings and steep
low to mid level lapse rates. Scattered afternoon thunderstorm
development is expected across the high terrain. Moderate
instability is progged along with strong deep layer shear, which may
support isolated stronger cells with potential for strong to severe
wind gusts.

...South Dakota and the Upper Midwest to the Great Lakes...
Strong daytime heating is expected across the northern Plains into
the Upper Midwest and Great Lakes Region. Daytime temperatures are
progged to possibly exceed 100 F south of the weak front from the
Dakotas into the Upper Midwest. With the building high amplitude
ridge, warming around the 850-700 mb level will result in capping
across much of the more strongly unstable air mass. It does appear
that portions of northern/central Minnesota into northern Wisconsin
and the Upper Peninsula of Michigan may see enough weakening of the
cap to allow for isolated thunderstorm development by the afternoon.
Forecast soundings suggest veering wind profiles favorable for
supercells. Strong deep layer shear and linearly elongated profiles
will support large to very large hail and damaging wind. Though
low-level shear is more marginal, low tornado potential will exist.

Additional isolated thunderstorms may develop near the Black Hills
in South Dakota. Very hot and moderately unstable conditions are
expected amid steep low to mid-level lapse rates. Isolated
supercells capable of large hail and damaging wind will be possible,
with potential for some clustering downstream and increase in
damaging wind potential into the evening.

...Southeast Arizona...
The favorable position of the surface high across the Four Corners
will bring moist easterly flow across southeastern Arizona. Some
enhancement of the easterly flow will allow for modest shear
profiles. It is likely that storms will develop across the high
terrain and move into the low deserts through the afternoon/evening.
Deeply mixed profiles and modest shear for organization will support
potential for strong to severe winds.

..Thornton.. 07/24/2026

$$